What happens if the depolarization does or does not reach the threshold?
What happens if the depolarization does or does not reach the threshold?
Depolarization is shift in the neuron membrane potential from positive to negative. In response to the depolarization, some sodium channels open which allow sodium ions to enter the cell. The membrane starts to depolarize. A normal threshold potential is -55mV.
If the depolarization reaches the threshold:
When the depolarization reaches its threshold (-55mV), a neuron generates an action potential. The membrane potential must be depolarized to generate an action potential. It is the temporary change in the neuron membrane potential caused by the sudden opening of the sodium channels. This results in the flow of information in neurons which is known as Electrical Synapse.
If the depolarization does not reach the threshold:
If the depolarization fails to reach the threshold potential that is sodium ion channels fails to open, there will be no gradual shift of neuron membrane potential from negative to positive. As a result, action potential will not be generated. It follows All or None principle. No threshold potential means there will be no generation of action potential. No electrical synapse will occur and there will no relay of information.
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